A bonding operation is a commonly-used process in manufacturing a Thin Film Transistor Liquid Crystal Display (TFT-LCD) module, and mainly refers to assembling a panel and a Flexible Printed Circuit (FPC) together or assembling the FPC and a Printed Circuit Board (PCB) together by means of an Anisotropic Conductive Adhesive (ACF) according to a certain workflow and enabling them to be electrically connected with each other.
However, a state of the bonding is mainly confirmed through viewing by a microscope. This viewing is complex and inefficient, resulting in a low yield. Since a substrate of a LCD panel currently is transparent, the state of the binding between the FPC and the panel may be viewed through the microscope. However, in case that a non-transparent PCB is used, it is a problem how to detect the state of the binding between the FPC and the non-transparent PCB.